In such a known station, one of the functions of the selector switch disconnectors and of the looping bay is to enable transfers to be made from one busbar to another under load, i.e. without interrupting distribution. When such a transfer is taking place under load, a selector switch disconnector must be opened while non-negligible current is passing through it. Unfortunately, during this operation, the disconnector is subjected to electrical wear which must be monitored.
It is known that the mechanical wear of such disconnectors can be monitored merely by counting the number of times each switch is operated. Nevertheless, that type of monitoring is unsatisfactory when numerous transfer operations are performed under load, and it turns out that the acceptable limit for electrical wear is reached before the maximum acceptable number of maneuvers is itself reached.
Also, for the purpose of protecting its circuit breakers, such a known station is fitted with a computer for each bay, which computers transfer state information to an operation monitoring station, such information including the positions of the disconnectors and of the circuit breakers included in the inlet and outlet bays, together with the values of the current in each bay.